1. Field of the Invention
This invention relates to mats with fasteners for securing elongate objects thereto; and, more particularly, to dash mats for vehicles having integral fasteners for securing electrical wire harnesses thereto and to a system for fastening together and acoustically sealing two vehicle dash mat pieces.
2. Description of the Related Art
In most contemporary automobiles, a steel firewall separates the engine compartment from the passenger compartment. To reduce the transmission of sound from the engine compartment through the firewall and into the passenger compartment, a sound barrier mat (otherwise known as a dash mat) is typically constructed of an elastomeric material and is mounted to and substantially overlies the firewall.
A wiring harness is typically arranged along a portion of the dash mat and extends from a fuse box to various components, such as radios, switches, lights, gauges, etc., within the passenger compartment. An outer surface of the dash mat is typically in contact with a bottom surface of the vehicle carpet and extends beyond the carpet to an upper portion of the firewall behind the instrument panel. It is common practice to secure the wiring harness to component mounting brackets, cable sheaths, and other protrusions within the passenger compartment via cable ties. It is also common to install the wiring harness to the sheet metal of a vehicle through Christmas-tree type push fasteners having a holding ring on an outer end of the fastener for receiving the wiring harness. It is often difficult to manipulate the cable ties and push fasteners in tight places, and the individual wires in the wiring harness can be undesirably strained while being secured. The mounting of wires in this manner is inefficient and leads to non-uniformity from vehicle to vehicle during assembly, since different protrusions within the passenger compartment from vehicle to vehicle may be used for securement. In addition, sharp edges resulting from excess material being trimmed from the installed cable ties can cause injury to repair personnel or others.
Different cable tie sizes are often required during wire harness assembly due to different wire harness configurations and the particular vehicle protrusions to which they are attached. The different sized cable ties result in a greater number of parts, and the use of cable ties results in a longer assembly time than desired.
Furthermore, apertures are formed in the dash mat and are aligned with openings in the firewall for the passage of cable guides, wiring harnesses, steering columns, accessory mounts, and the like. Since the dash mat is designed to insulate the passenger compartment from engine compartment noise, it is desirable to size the apertures as small as possible to fir snugly around the various elements projecting through the apertures without compromising the ease and efficiency of install such elements. One difficult area is the opening formed in the dash mat for receiving the steering column, which is typically quite large when compared to other openings in the dash mat. Maintaining the noise reduction qualities of the mat in this area is difficult due to the size of the opening. Typically, a modular plate barrier, which is provided with a smaller steering column and mounting apertures, is used to cover the larger dash mat opening. After installation of the steering column and instrument panel, it is desirable to securely seal the modular plate barrier to the rest of the dash mat.